Drive device for a movable furniture part

ABSTRACT

The invention relates to a drive device for a moveable furniture part comprising an ejection element, an ejection force accumulator and a locking device for the ejection element. Said locking device comprises a locking journal which is subjected to force of the ejection force accumulator and can be locked in a locked position in a latch region of a guide track. Said guide track is shaped like a curved heart and comprises a tightening section in which the locking journal can be moved when the ejection force accumulator is tightened, and a latching movement section of the locking journal prior to reaching the locked position in the latch region. The locking journal impinged upon by the tightened ejection force accumulator can be slowed down and/or dampened in the latching movement section and can be placed in the latch region.

The invention concerns a drive device for a moveable furniture partcomprising an ejection element, an ejection force storage means and alocking device for the ejection element, wherein the locking device hasa locking pin which is acted upon by the ejection force storage meansand which is lockable in a locking position in a latching region of aguide path, wherein the guide path is of a cardioid-shaped configurationand the cardioid-shaped guide path has a stressing portion in which thelocking pin is moveable upon stressing of the ejection force storagemeans and a latching engagement movement region of the locking pinbefore the locking position in the latching region is reached. Theinvention further concerns an article of furniture comprising afurniture carcass, a furniture part moveable relative to the furniturecarcass and such a drive device for the moveable furniture part.

Drive devices for ejecting a moveable furniture part from a closedposition into an open position have already been known for many years inthe furniture fitting industry. To guarantee that the ejection elementor the moveable furniture part is securely held in a closed positionlocking devices are provided in that arrangement. When opening of themoveable furniture part is wanted the locking device can then beunlocked by actuation of a triggering mechanism. Unlocking can beeffected for example by pressing against the moveable furniture part topush it into an over-pressing position. Triggering or unlocking is alsopossible by pulling. After such unlocking an ejection force storagemeans can deliver its force and in so doing move the moveable furniturepart in the opening direction by way of the ejection element.

After the ejection force storage means has been relieved of its loadupon opening of the moveable furniture part that ejection force must berestored to the ejection force storage means again by stressing. That isgenerally effected when closing a moveable furniture part (but it canalso be effected upon opening) by an operator who moves the moveablefurniture part by hand. When therefore a pressing force is applied tothe moveable furniture part upon closure thereof, pressure is alsoapplied against the force of the ejection force storage means. As soonas the ejection force storage means is fully stressed the locking pin ofthe locking device passes along the guide path into the latching region,in which case then the hand no longer holds the ejection force storagemeans in its stressed position but the locking pin locks or holds thestressed ejection force storage means in the locking position at thelatching region.

A critical region in terms of stressing and locking is the regionimmediately prior to reaching the locking position in the latchingregion. More specifically if the latching pin, by virtue of theconfiguration of the guide path, passes into a region shortly beforereaching the latching region then the ejection force storage means canact with a relatively high force on that locking pin, in which case thatthen comes into an abutment condition in the latching region with theproduction of a relatively large amount of noise and heavy wear.

DE 10 2011 002 212 R1 discloses a spring element which forms a latchingrecess but which only serves to also permit pulling unlocking.

WO 2007/112463 A2 entails the problem of noise generation, but for thatpurpose the entire moveable furniture part is braked before the ejectionforce storage means is loaded.

Therefore the object of the present invention is to provide a drivedevice which is improved over the state of the art. In particular theinvention seeks to provide that locking can be effected as quietly aspossible. The invention further seeks to provide that locking can beeffected with the lowest possible loading on the components involved.

That is attained by a drive device having the features of claim 1.Accordingly it is provided that the locking pin which is acted upon bythe stressed ejection force storage means in braked and/or dampedrelationship is moveable in the latching engagement movement region andcan be placed in the latching region. Accordingly the full force of theejection force storage means no longer acts on the locking pin when thelatching region is reached, but the movement of the locking pin isdamped or braked before reaching the latching region.

With such a cardioid-shaped guide path it is preferably provided thatthe latching region is spaced in the opening direction of the moveablefurniture part from a transitional region which is between the stressingportion and the latching engagement movement region, preferably bybetween 0.2 mm and 3 mm. As the locking pin can be preferably completelyuncoupled from a movement of the moveable furniture part as fromreaching the transitional region and as therefore the locking pin ismoveable into the latching region by the ejection force storage meansalong the latching engagement movement region it is precisely thatspacing between the transitional region and the latching region in theprevious cardioid-shaped guide paths that is the reason that relativelysevere striking and locking noises occur by virtue of the high forcewhich acts on the locking pin from the ejection force storage means. Thegreater the force of the ejection force storage means, the louder andmore disturbing can the locking noises be. That is now prevented by thebraking or damping action in respect of the locking pin.

In principle a plurality of different ways in which the locking pin canbe placed in the latching region in braked or damped relationship areconceivable.

A first variant provides that there is provided a damping device whichis operative between the ejection force storage means and the lockingpin and which damps the kinetic energy transmitted from the ejectionforce storage means into the locking pin before the locking position isreached. Thus it is not the full energy that is transmitted to thelocking pin as from attainment of the transitional region. In otherwords the kinetic energy acting on the locking pin is reduced by thedamping device. It is particularly preferably provided for that purposethat the kinetic energy acting on the locking pin is reduced by thedamping device only in the latching engagement movement region of thelocking pin. That damping device also does not have to damp the movementof the locking pin in the entire latching engagement movement region,but can also damp it only in a part of that region. A particularlypreferred embodiment of such a damping device provides that the dampingdevice is in the form of a travel transmission mechanism. Thus it is notthe entire energy that is immediately transmitted to the locking pinfrom the ejection force storage means. That can be effected for exampleby an arrangement whereby the locking pin can be placed in the latchingregion in cam-controlled relationship by the travel transmissionmechanism, wherein the travel transmission mechanism has a control camby which the kinetic energy acting from the ejection force storage meanson the locking pin is preferably steadily increased along the latchingengagement movement region in dependence on the control cam. A furthervariant for this slow delivery of the energy from the ejection forcestorage means to the locking pin provides that a damper, for example inthe form of a linear damper, is arranged for example in the region ofthe ejection force storage means or at its head. Thus the first part ofthe stress relief travel of the ejection force storage means is fromfull stressing to almost full stressing which is achieved in the closedposition.

A second variant for placing the locking pin in the latching region inbraked and/or damped relationship provides that the transfer of kineticenergy to the locking pin is not delayed or controlled, but rather themovement of the locking pin itself—on which the full force of theejection force storage means is already acting—is damped or braked. Forthat purpose an alternative configuration provides that the dampingdevice has a moveable damping element, preferably a rotational damper,wherein the damping element includes a gear which is mounted in dampedrotary relationship, wherein at least one tooth of the gear can becontacted by the locking pin in the latching engagement movement regionand is moveable in damped relationship in the direction of the latchingregion. Thus in practice the tooth of the gear in the latchingengagement movement region forms a kind of brake so that the locking pincannot move unimpededly into the latching region. As the locking pin ispreferably arranged on a pivotable locking lever the locking pin dampingaction can also be produced by the provision of a rotational damper or afriction brake in the region of the axis of rotation of the lockinglever.

In principle preferably there are provided a base plate and a sliderforming the ejection element, to give a structurally simpleconfiguration, wherein the slider is moveable relative to the base plateand is lockable by way of the locking device to the base plate. In thatcase the ejection force storage means which is preferably in the form ofa tension spring is fixed on the one hand to the base plate and on theother hand to the slider. To permit the movement of the locking pin inthe guide path it is preferably provided that the locking pin is mountedrotatably to the slider by way of a locking lever and engages into theguide path in the base plate. In that case, as stated, the movement ofthe locking lever can also be damped by way of a damping device.

In principle it can further be provided that the ejection force storagemeans can be loaded by opening and/or closing the moveable furniturepart. It is also possible that the entire drive device can be unlockedor triggered by over-pressing the moveable furniture part into anover-pressing position which is behind the closed position in a closingdirection and/or by pulling on the moveable furniture part into an openposition in front of the closed position.

Protection is also claimed for an article of furniture having afurniture carcass. In that respect it can be provided that the essentialcomponents of the drive device are arranged on the furniture carcass andthe moveable furniture part can be ejected by way of an entrainmentportion mounted to the moveable furniture part or the drawer rail. In apreferred embodiment of the present invention however it is providedthat the base plate of the drive device is arranged on the moveablearticle of furniture and an entrainment portion which can be broughtinto engagement with the ejection element is arranged on the furniturecarcass. Thus the moveable furniture part virtually itself pushes itselfaway against the furniture carcass by way of the drive device.

Further details and advantages of the present invention will bedescribed more fully hereinafter by means of the specific descriptionwith reference to the embodiments by way of example illustrated in thedrawings in which:

FIG. 1 shows an article of furniture with moveable furniture parts invarious positions,

FIG. 2 shows a 3D view of a moveable furniture part,

FIG. 3 shows the moveable furniture part from below with a drive device,

FIG. 4 shows an exploded view of the drive device,

FIG. 5 through 18 show the drive device in various positions,

FIG. 19 shows an exploded view of a second embodiment of the drivedevice,

FIG. 20 shows details of the second drive device,

FIGS. 20 a-20 g show an embodiment of the damping device produced usingtwo-component injection molding,

FIGS. 20 h-20 k show an embodiment of the damping device produced usingmulti-component injection molding,

FIGS. 21 through 26 show a different position of the second drivedevice,

FIGS. 27 through 28 show a further embodiment of a damping device,

FIGS. 29 through 30 show a damping device in the form of a cushionedabutment,

FIG. 31 diagrammatically shows the basic principle of the presentinvention,

FIG. 32 shows a graph illustrating the spring force of the ejectionforce storage means matching the first variant, and

FIGS. 33 through 40 show further examples for triggering by pulling.

FIG. 1 shows an article of furniture 17 with a plurality of moveablefurniture parts 2 in the form of drawers, mounted moveably to thefurniture carcass 18. In this case the individual moveable furnitureparts 2 are respectively fixed to the furniture carcass 18 by way of anextension guide means 24, the extension guide means 24 including atleast a carcass rail 22 and a drawer rail 23. There may possibly also bea central rail. The moveable furniture part 2 itself has at least onedrawer container 20 and a front panel 21. The moveable furniture part 2which is shown right at the top is in an open position OS and it can bediagrammatically seen that the drive device 1 is mounted to the drawercontainer 20 or the drawer rail 23. As essential components the drivedevice 1 has a base plate 14 and an ejection element 3 moveable relativeto the base plate 14. That ejection element 3 is in the form of adisplaceable slider and is acted upon by the ejection force storagemeans 4. The ejection element 3 is in engagement by way of anentrainment portion 19 with the carcass rail 22 and with the furniturecarcass 18 respectively. Upon ejection the drive device 1 bears againstthe entrainment portion 19 by way of the ejection element 3 and theejection force storage means 4 which in this case is in the form of acompression spring and moves the moveable furniture part 2 in theopening direction OR. That ejection element 3 is lockable to the baseplate 14 by way of a locking device 5. For that purpose the lockingdevice 5 has a locking lever 16 mounted pivotably to the slider 15, thelocking pin 7 disposed at the front end of the locking lever 16 and theguide path 6, in the base plate 14, together with the latching region R.When the moveable furniture part 2 is moved from the position shown bythe uppermost drawer into the position therebeneath, then in thatmovement in the closing direction SR the slider 15 is moved towards theright relative to the base plate 14, with the ejection force storagemeans 4 being stressed. As soon as the locking pin 7 passes into thelatching region R of the guide path 6 the locking position V of thelocking device 5 is reached. That can already be the case when themoveable furniture part 2 is still open, in particular when the moveablefurniture part 2 is moved from the second illustrated position into thethird illustrated position by a retraction device 25 (onlydiagrammatically indicated here) into the closed position SS. Thelowermost illustration in FIG. 1 shows the triggering position orover-pressing position ÜS in which a pressure is applied to the moveablefurniture part 2 in the closing direction SR thereby to unlock thelocking device 5. It is however also possible to provide for unlockingby pulling.

FIG. 2 shows a 3D view of the moveable furniture part 2, in whichrespect it can be seen that the moveable furniture part 2 comprises adrawer container 20 and the front panel 21. It can further be seen thatthe moveable furniture part 2 is connected to an extension guide means24.

FIG. 3 shows the moveable furniture part 2 from below, with the drivedevice 1 together with the base plate 14 being mounted on the drawerbottom 27. Fixed to the carcass rail 22 is the entrainment plate 26 towhich the entrainment portion 19 is mounted.

FIG. 4 shows an exploded view of the drive device 1, wherein the twomain components are the base plate 14 and the slider 15 forming theejection element 3. The linear movement of those two components 14 and15 relative to each other is limited at least by the slider path limiter37 mounted to the base plate 14 and the slider path 36 in the slider 15.A further important component is the ejection force storage means 4which is held at the spring base 31 on the base plate 14 and the springbase 32 on the slider 15. That ejection force storage means 4 is in theform of a tension spring. The locking lever 16 with locking pin 7 andthe cardioid-shaped guide path 6 are provided as the locking device 5.The locking lever 16 is mounted rotatably or pivotably at the rotarybearing 28 in the slider 15. In the mounted condition the locking pin 7engages into the guide path 6. There is further provided a transmissionelement 42 which is limitedly moveably mounted by way of the guidelimiting means 52 to a path (not shown) provided at the underside of theslider 15. The coupling element 33 is pivotably mounted to thattransmission element 42 at the pivot bearing 73. That coupling element33 has the catch region 34 for the entrainment portion 19 (not shown).The pivotal movement of the coupling element 33 is controlled by way ofthe guide element 74 as the guide element 74 is guided in the couplingelement guide path 35 in the slider 15. There is also a connectingelement 41 mounted rotatably in the rotary bearing 44. A stressingabutment 55 is provided on that connecting element 41. Provided as afurther component is the control element 29 which is moveable ordisplaceable by way of the guide elements 57 in the control elementguide path 30 in the base plate 14. Also mounted to the control element29 is the stressing element 56 which, upon stressing of the ejectionforce storage means 4, bears against the stressing abutment 55 of theconnecting element 41. The control element 29 also has the control cam9, against which the abutment 43 on the transmission element 42 bearsdepending on the respective position. Those two components 43 and 9together form a kind of travel transmission mechanism and thereby thedamping device 8 for moving the locking pin 7 into the latching region Rin damped relationship (this will be described in greater detail in thefollowing Figures). In addition the first pulling triggering element 46is mounted rotatably to the base plate 14 by way of the rotary bearing19. That first pulling triggering element 46 has the two limitingelements 61, between which the abutment 43 of the transmission element42 is positioned in the closed position SS. There is also a secondpulling triggering element 47 on which is provided the locking abutment45 which also forms the latching region R. That locking abutment 45 thusforms a part of the guide path 6 and is moveable relative to the baseplate 14. The displacement of that second pulling triggering element 47is limited by the guide abutment 75 and the side surface 76 of the baseplate 14. In addition that second pulling triggering element 46 ispressured by way of the compression spring 48, wherein that compressionspring 48 is fixed or held on the one hand at the spring base 50 and onthe other hand at the spring base 51 on the second pulling triggeringelement 47. Lastly the drive device 1 also has a retraction device 25which as essential components has the retraction force storage means 40,the retraction coupling element 39 and the cover element 38, wherein thecover element 38 is held by way of the holding clips 77 to the openings78 in the base plate 14. The retraction force storage means 40 is in theform of a tension spring.

Referring to FIG. 5 the entire moveable furniture part 2 is in an openposition OS, with the moveable furniture part 2 still being in thefree-running condition. In other words, there is still no contact withthe diagrammatically illustrated entrainment portion 19. The ejectionforce storage means 4 is still relieved of stress, but pulls on theslider 15 until the end of the slider path 36 bears against the sliderpath limiting means 37. The locking pin 7 is guided in a stressingportion S of the guide path 6. The stressing element 56 of the controlelement 29 still does not bear against the stressing abutment 55 of theconnecting element 41, but in contrast the abutment 43 of thetransmission element 42 already bears against the control element 29 andthere at the beginning of the control cam 9. By virtue of thecompression spring (not shown) operative between the spring base 53 andthe spring base 54 the connecting element 41 is pivoted towards the leftabout the rotary bearing 44. It can further be seen in the detailed viewat bottom right that the guide path 6 has the latching engagementmovement region E after the stressing portion S and the transitionalregion Ü. The latching region R formed by the locking abutment 45mounted to the second pulling triggering element 47 is disposed at theend of that latching engagement movement region E. That latching regionR is followed by the ejection portion A, wherein the locking pin 7passes into that ejection portion A by way of the diversion surface 79.It is only upon unlocking by over-pressing that the locking pin 7 meetsthat diversion surface 79. In contrast upon unlocking by pulling thelocking abutment 45 is pulled away downwardly so that the path for thelocking pin 7 into the ejection portion A is also free and the ejectionforce storage means 4 can be relieved of stress. FIGS. 6 through 18which are described hereinafter do not always show all references.Naturally however the references always correspondingly apply for eachof FIGS. 5 through 18.

If now as shown in FIG. 6 the moveable furniture part 2 is movedtogether with the drive device 1 in the closing direction SR then thecoupling element 23 comes into abutment with the entrainment portion 19which is fixed with respect to the carcass. As a result by virtue of theconfiguration of the coupling element guide path 35 and the guideelement 74 guided therein the coupling element 33 is pivoted about thepivot axis 73 and the entrainment portion 19 is caught in the catchregion 34 of the coupling element 33. The coupling element 33 hasalready moved together with the transmission element 42 as shown in FIG.6 by a considerable distance relative to the FIG. 5 position, by virtueof the manual closing movement of the moveable furniture part 2 in theclosing direction SR. The control element 29 is also moved by thatmovement, by way of the abutment 43. As once again the stressing element56 is provided on that control element 29 the connecting element 41 isalso moved by way of the stressing abutment 55. As that connectingelement 41 is again mounted in the rotary bearing 44 on the slider 15the entire slider 15 and therewith the ejection element 3 are displacedrelative to the base plate 14, with stressing of the ejection forcestorage means 4. By virtue of that displacement, the locking pin 7 alsoalready passes further along the stressing portion S into the proximityof the transitional region Ü. It can also already be seen from FIG. 6that the control element 29 pivots slightly by way of the guide element57 and the control element guide path 30.

Referring to FIG. 7 that pivotal movement of the control element 29 hasalready further continued, whereby the abutment 43 of the transmissionelement 42 has already moved along the control cam 9 on the controlelement 29. At the same time the locking pin 7 has also already movedbeyond the transitional region Üand is at the beginning of the latchingengagement movement region E. In previous embodiments, at that momentthe ejection element 3 and the slider 15 were uncoupled from thepressing movement of an operator and the slider 15 was free. As a resultthe full ejection force of the ejection force storage means 4 could acton the locking pin 7 and move same quickly and with a large amount offorce along the latching engagement movement region E into the latchingregion R. As a result, in previous embodiments, there was thedisadvantage of a large amount of noise being produced and a severeloading on the parts of the locking device 5. In comparison it will beseen from FIG. 7 that the slider 15 was admittedly already slightlydecoupled from the transmission element 42 and its abutment 43 by way ofthe ejection force storage means 4, but entire decoupling has not yetoccurred by virtue of the configuration of the control cam 9. Rather,the abutment 43 and the control cam 9 form a travel transmissionmechanism and thereby a kind of damping device 8 for the locking pin 7.As a result the kinetic energy operative from the ejection force storagemeans on the locking pin 7 increases only slowly.

This can also be seen from FIG. 8 wherein the abutment 43 has againmoved further along the control cam 9 and at the same time there hasbeen a further movement of the locking pin 7 in the latching engagementmovement region E. The fact that the ejection force storage means 4 hasalready moved the slider 15 again relative to the base plate 14 can alsobe seen from the fact that the slider path limiting means 37 has movedrelative to the slider path 36, in relation to FIG. 7.

In FIG. 9 there is no longer any contact between the abutment 43 and thecontrol cam 9 of the control element 29 whereby the full force of theejection force storage means 4 is acting on the locking pin 7 by way ofthe slider 15, the rotary bearing 28 and the locking lever 16. As, atthe moment of full force being exerted by the ejection force storagemeans 4 on the locking pin 7, that locking pin 7 however is already inthe latching region R, no loud noises are produced and there is no heavywear. In that position as shown in FIG. 9 the control element 29 isloose and is not subjected to force in the control element guide path30. It will further be seen that, by virtue of the further movement ofthe transmission element 42, the connecting element 41 pivots in theclockwise direction against the force of the compression spring (notshown). That takes place as the diversion abutment 58 on the connectingelement 41 is moved or diverted by the diversion surface 59 on thetransmission element 42. It can further be seen from FIG. 9 that thelocking device 5 is admittedly already in the locking position V, butthe moveable furniture part 2 is still in an open position OS. By virtueof the manual closing movement however the coupling element 33 hasalready moved relative to the base plate 14 to such an extent that theretraction coupling element 39 has moved out of the angled end portion80 of the retraction device 25 so that the retraction coupling element39 is coupled to the coupling pin 60 on the coupling element 33. Becausethe retraction coupling element 39 is now no longer in the angled endportion 80 the retraction force storage means 40 can also be relieved ofstress, contracting as it does so, so that the entire moveable furniturepart 2 is further moved in the closing direction SR and reaches theposition shown in FIG. 10. That position corresponds to a positionshortly before reaching the closed position SS. It will also be seenfrom this FIG. 10 that, by virtue of the further movement of thetransmission element 42 relative to the slider 15, the connectingelement 41 has been further pivoted in the clockwise direction by way ofthe diversion abutment 58. As a result the stressing element 56 of thecontrol element 29 comes out of engagement with the stressing abutment55 of the connecting element 41. FIG. 10 further shows that the abutment43 of the transmission element 42 is now between the limiting elements61 of the first pulling triggering element 46, wherein the arm 81 of thefirst pulling triggering element 46 bears laterally against the elasticarm 62 of the second pulling triggering element 47.

When now the retraction force storage means 40 is relieved of stress asshown in FIG. 11 the closed position SS as shown in FIG. 11 is reached.As shown in FIG. 11 the first pulling triggering element 46 has alsorotated about the rotary bearing 49 in the counter-clockwise directionby virtue of the pressure exerted by way of the abutment 43 and thetransmission element 42, wherein the arm 81 now bears against the frontside of that elastic arm 62, with flexing of the elastic arm 62.

If now a pressing force is applied to the moveable furniture part 2 inthe closing direction SR starting from that closed position SS as shownin FIG. 11 then the moveable furniture part passes into theover-pressing position ÜS as shown in FIG. 12. As the transmissionelement 42 has already reached the end of the path in the slider 15 byway of the guide limiting means 52 as shown in FIG. 11, then in theover-pressing situation the entire slider 15 is moved relative to thebase plate 14, whereby the locking pin 7 also passes out of the latchingregion R into the ejection portion A by way of the diversion surface 79.

As an alternative thereto, as shown in FIG. 13, unlocking can also beeffected by pulling. In that case, starting from the position shown inFIG. 11, the moveable furniture part 2 is pulled, in which case thetransmission element 42 and its abutment 43 are moved relative to theslider 15 by way of the coupling element 33. As the abutment 43 as shownin FIG. 11 is still caught between the limiting elements 61, the firstpulling triggering element 46 is rotated in the clockwise directionabout the rotary bearing 49 by that pulling movement. As the arm 81 ofthat first pulling triggering element 46 bears against the end of theelastic arm 62—which, when it is acted upon with force by that end doesnot elastically yield but remains stiff—of the second pulling triggeringelement 47, that pulling triggering element 47 is moved relative to thebase plate 14 against the force of the spring 48 which is compressed inFIG. 13, whereby the locking abutment 45 also moves away from thelatching region R. As a result the locking pin 7 is no longer held orlocked in the latching region R and it passes into the ejection portionA by virtue of the spring force of the ejection force storage means 4.

Irrespective of whether the locking device 5 was unlocked by pulling orby over-pressing, the drive device 1 then at any event passes into theopen position OS as shown in FIG. 14. With that movement, the firstpulling triggering element 46 is also further rotated in the clockwisedirection by way of the abutment 43, whereby the second pullingtriggering element 47 is moved against the force of the spring 48 untilthe first pulling triggering element 46 passes into the position shownin FIG. 14.

During that ejection movement the retraction force storage means 40 ofthe retraction device 25 is also stressed by way of the coupling pin 16.The locking pin 7 passes into the stressing portion S again (see FIG.15).

In FIG. 16 the retraction coupling element 39 is again uncoupled fromthe coupling pin 60 of the coupling element 33 and the retractioncoupling element 39 is held in the angled end portion 80 with theretraction force storage means 40 in the stressed condition. In FIG. 16the ejection force storage means 4 is not yet entirely relieved ofstress.

In FIG. 17 however the ejection force storage means 4 has been relievedof stress to such an extent that now the slider 15 bears against thebase plate 14 by way of the slider path 36 and the slider path limitingmeans 37, in an end position. The moveable furniture part 2 is nowfreely moveable or for example can move still further in the openingdirection OR due to the inertia triggered by the ejection force storagemeans 4. As the entrainment portion 19 is still held in the catch region34 of the coupling element in the further movement in the openingdirection OR the coupling element 33 together with the transmissionelement 42 is moved further relative to the slider 15, in which case theabutment 43 already comes into contact with the abutment 63 on thecontrol element 29, as shown in FIG. 16, whereby the control element 29is also moved along the control element guide path 30 by thetransmission element 42 relative to the slider 15.

As shown in FIG. 18 the transmission element 42 has moved relative tothe slider 15 until the control element 29 is again at the height of theconnecting element 41. At the same time the spring (not shown) betweenthe connecting element 41 and the slider 15 has also been relieved ofstress by virtue of the diversion abutment 58 which is no longerdeflected by the diversion surface 59. In FIG. 18 the coupling element33 has also reached the angled end portion of the coupling element guidepath 35 so that the coupling element 33 has been pivoted about the pivotbearing 73 so that the entrainment portion 19 is released from the catchregion 34 of the coupling element 33. The initial position shown in FIG.5 is thus restored.

Another way of not immediately causing the entire force of the ejectionforce storage means 4 to act on the locking pin 7—as in the case of thetravel transmission mechanism—provides that the ejection force storagemeans itself is damped. For that purpose in particular in the firstrange of movement of the ejection force storage means 4, acting in theopening direction OR, going from the over-pressing position ÜS to theclosed position SS, a damping device 8 can reduce the transmission offorce from the ejection force storage means 4 to the slider 15. That isdiagrammatically shown in FIG. 32. It will be seen from the graph inFIG. 32 how the spring force F of the ejection force storage means 4acts along the path of movement of the moveable furniture part 2. Innormal ejection illustrated by the broken line, when the moveablefurniture part 2 is released in the over-pressing position ÜS, a highforce on the part of the ejection force storage means 4 becomes freewhereby the spring force F rises to a high Newton value N even beforethe closed position SS is reached. As the same applies for thetransmission of force from the ejection force storage means 4 to thelocking pin 7 not only in the region between the over-pressing positionÜS and the closed position SS, but also for the substantially identicaldrawer travel movement region between the transitional region Ü and thelatching region R, it will be apparent that, when the latching region Ris reached by the ejection force storage means 4, a very high springforce F acts on the locking pin 7 and on the guide path 6 in thelatching region R, which can cause loud knocking noises. In order toreduce that high transmission of force in that latching engagementmovement region E either the travel transmission mechanism which has adamping effect in accordance with the first embodiment is provided or adamping device 8 (for example a linear damper) between the ejectionforce storage means 4 and the slider 15 is provided. For example thatdamping device 8 can be integrated into the ejection force storage means4 or connected in parallel therewith.

A further embodiment of a drive device 1, in which the locking pin 7 canbe placed in the latching region R in braked and/or damped relationshipis shown as an exploded view in FIG. 19. In this case once again theguide path 6 with latching region R is provided in the base plate 14.That base plate 14 can be displaced relative to the moveable furniturepart 2 by way of the depth adjusting wheel 65 so that it is possible toadjust the front panel gap. The ejection element 33 or the slider 15 ismounted displaceably relative to the base plate 14 along the couplingelement guide path 35. The coupling element 33 is also mounted pivotablyon the slider 15. In addition the synchronization element 67 is alsoconnected to the slider 15. Drive devices 1 arranged on opposite sidesof the moveable furniture part 2 can be coupled or synchronized by wayof that synchronization element 67. The locking lever 16 is mountedrotatably or pivotably to the slider 15 by way of the locking leverpivot bearing 70. The locking pin 7 is also fixed to the locking lever16. The ejection force storage means 4 is operative between the slider15 and the base plate 14. In this embodiment, provided as an additionalelement is a base plate cover 64 in which the damping device 8 isprovided. For that purpose the base plate cover 64 has a gear rotarybearing 66 at which the gear 11 is rotatably mounted. That gear 11 andthe gear rotary bearing 66 together with a damping medium therebetweenform the rotational damper 10. To achieve a good connection between thegear 11 and the bearing 66 the arrangement has the holding element 68which presses the gear 11 on to the bearing 66.

FIG. 20 is a detail view showing that the gear 11 and the bearing 66have corresponding concentric grooves. To provide a good damping actiona suitable, preferably viscous damping medium, for example Opanol, ispresent in or introduced into those grooves. It can also already be seenfrom FIG. 20 that an opening 69 is provided in the base plate cover 64.The edge of that opening 69 substantially coincides with a part of theguide path 6 and is provided sufficiently accurately opposite or abovethat region of the guide path 6 in the base plate 14, in the base platecover 64. The edge of the opening 69 therefore also corresponds in aregion thereof to the latching engagement movement region E, into which,in the assembled condition, a tooth 12 of the gear 11 projects.

FIGS. 20 a through 20 g show a further embodiment of a damping device 8.In this variant it is possible to dispense with the use of a dampingmedium insofar as the damping action is produced by friction between twocomponents which are preferably produced in a two-component injectionmolding. FIGS. 20 a and 20 b show the star-shaped gear 11 and theholding element 68 which jointly form the rotational damper 10. Theholding element 68 made from steel has a bent-up extension portion 83and an opening, wherein the extension portion 83 at the same time formsthe gear rotary bearing 66. It will be seen from the sections in FIGS.20 c and 20 d that the extension 83 projects into the gear 11 whichcomprises plastic. Shortly after the two-component injection moldingoperation the bent-up extension portion 83 and the gear contact eachother substantially over the entire surface (see FIG. 20 e). Due to thecontraction or shrinkage 84 of the plastic material after the injectionmolding operation the connection between the bent-up extension portion83 and the gear 11 is at least partially released (see FIG. 20 f). Thatresults in an undersize in relation to the sheet metal thickness. As aresult the gear 11 can rotate relative to the holding element 68. Thetorque can be adjusted by adaptation of the wall thickness and thechoice of material. FIG. 20 g shows the damping device 8 in theinstalled condition on the base plate cover 64.

A possible design configuration for the damping device 8 in the form ofa multi-component injection molding is shown in FIGS. 20 h through 20 k.In these views the gear rotary bearing 66 is not in the form of part ofthe holding element 68, but is “added by injection” as a separateplastic part to the holding element 68 and projects through an openingin the holding element 68. A further plastic part forming the gear 11 isalso mounted rotatably to that plastic part forming the bearing 66. Thedamping action is produced by friction between the gear 11 and thebearing 66.

A damping medium is no longer necessary with those design configurationsfor the damping device 8, there are slight torque fluctuations, there isa low degree of temperature sensitivity and a longer service life isachieved.

Referring to FIG. 21 the moveable furniture part 2 is in an openposition OS, the locking pin 7 still being at the beginning of astressing movement of the ejection force storage means 4. It is alsoalready apparent that a tooth 12 of the gear 11 projects into thelatching engagement movement region E of the guide path 6.

When now the moveable furniture part 2 is moved in the closing directionSR the entrainment portion 19 is caught in the catch region 34 of thecoupling element 33. At the same time the locking pin 7 moves along thestressing portion S (see FIG. 22).

Referring to FIG. 23 the locking pin 7 has moved past the transitionalregion Ü and thereby passes into the latching engagement movement regionE in which the full force of the ejection force storage means 4 acts onthe locking pin 7. That force however can act only until the locking pin7 bears against the tooth 12 projecting into the latching engagementmovement region E. More specifically, as soon as the locking pin 7 bearsagainst that tooth 12 the movement of the locking pin 7 is braked byvirtue of the damping action of the rotational damper 10 and the lockingpin 7 moves only slowly in the direction of the latching region R.

As soon as the gear 11 has moved in the counter-clockwise direction,with damping of the movement of the locking pin 7, until it no longerprojects into the latching engagement movement region E, the locking pin7 is in the latching region R of the guide path 6 as shown in FIG. 24.Thus the movement of the locking pin 7 is braked at least in a part ofthe latching engagement movement region E by the damping device 8 in theform of the rotational damper 10.

FIG. 25—as is known per se—shows the over-pressing position ÜS in whichthe locking pin 7 moves from the latching region R by way of thediversion surface 79 into the ejection portion A by over-pressing of themoveable furniture part 2 into an over-pressing position ÜS which isbehind the closed position SS in the closing direction SR.

In FIG. 26, an open position OS is then again reached, in which thelocking pin 7 passes into the region of the initial position again. Amore detailed description of the remaining components and the remainingprocedural movements of this embodiment as shown in FIGS. 19 through 26will not be set forth here as the basic implementation substantiallycorresponds to the first embodiment and for that reason attention iscorrespondingly directed in substance thereto.

A further alternative embodiment of a possible way of placing thelocking pin 7 in the latching region R in braked or damped relationshipis shown in FIGS. 27 and 28. The basic structure in this embodiment alsocorresponds to the embodiment of FIGS. 19 through 26, it is only thedamping device 8 that is of a different configuration. In thisembodiment there is no rotational damper 10 in the region of thelatching engagement movement region E, but the pivotal movement of thelocking lever 16 is damped by a damping device 8. For that purpose thedamping device 8 is disposed in the region of the axis of rotation D ofthe locking lever 16 on the synchronization element 67 or on the slider15. More specifically FIG. 28 shows a sectional view illustrating that apin 71 forms the axis of rotation D for the locking lever 16. A frictionbrake 72 is arranged in an annular configuration between that pin 71 andthe locking lever 16. The pivotal movement of the locking lever 16 canbe damped by virtue of the fact that the friction brake 72 is verystrongly clamped into the region between the locking lever 16 and thepin 71. As a result the locking pin 7 is moved in a reduced-speedmovement along the latching engagement movement region E. It will beappreciated that other kinds of shaft dampers are also conceivable.

A further variant which is not according to the invention for moving thelocking pin into the latching region R in braked or damped relationshipis shown in FIGS. 29 and 30. In that case the transmission of force fromthe ejection force storage means 4 to the slider 15 is not damped andalso the locking pin 7 is not braked in the latching engagement movementregion E, but rather provided in the latching region R is a dampingdevice 8 in the form of a cushioning 13 or an elastically yieldingelement. In that respect it can be seen from FIG. 29 how the locking pin7, after passing beyond the transitional region Ü, reaches the latchingengagement movement region E. In that region E the locking pin 7 movesat full speed and under full load in the direction of the latchingregion R, where it arrives as shown in FIG. 30. To reduce the generationof noise the cushioning 13 is provided in the latching region R.Abutting contact is damped thereby.

The fundamental concepts of the present invention are diagrammaticallysummarized once again in FIG. 31. It is essential that locking of thelocking pin 7 in the latching region R of the guide path 6 is effectedas quietly as possible.

For the purpose, in accordance with a first embodiment (FIGS. 3 through18 and FIG. 32), there is provided a damped movement region B along thelatching engagement movement region E. In this case that can be effectedby the fact that it is not the full force of the ejection force storagemeans 4 that acts on the locking pin 7 or the guide path 6, for exampleby way of a travel transmission mechanism or a linear damper, along thatlatching engagement movement region E.

In a further embodiment (FIGS. 19 through 28) the movement of thelocking pin 7 in that movement region B can be braked at leastportion-wise by a damping device 8 for example in the form of arotational damper or a pivotal movement damper.

As a third variant which is not according to the invention (see alsoFIGS. 29 and 30) abutment in the latching region R can be damped initself. For that purpose the damping device 8 can be in the form of acushioning 13 or an elastic element fitted to the wall of the guide path6.

FIG. 13 shows an embodiment for unlocking and ejection by pulling. Afurther variant for unlocking by pulling is shown in FIGS. 33 through36, whereby the drive device 1 has a pulling triggering element 46rotatable about the rotary bearing 49. That triggering element 46engages by way of an arm 81 into an opening in the pulling triggeringelement 47. The locking abutment 45 is provided on that pullingtriggering element 47. When, starting from the closed position SS asshown in FIG. 34 a pulling force is applied to the moveable furniturepart 2 in the opening direction OR the pulling triggering element 46 isrotated by the abutment 43 in the clockwise direction about the bearing49 so that, by way of the arm 81, the pulling triggering element 47 ismoved against the force of the spring 48 (see FIG. 35). As a result thelocking abutment 45 is also moved and enables a passage for the lockingpin 7. In that way the ejection force storage means 4 can be relieved ofstress and the moveable furniture part 2 is moved into an open positionOS, in which case the locking pin 7 passes into the position shown inFIG. 36.

A further pulling triggering variant is shown in FIGS. 37 through 40wherein the locking abutment 45 is provided on a pulling triggeringelement 47 moveable transversely relative to the closing direction SR.When, starting from the closed position SS as shown in FIG. 38 a pullingforce is applied to the moveable furniture part 2 in the openingdirection OR, then the locking pin 7 itself moves the pulling triggeringelement 47 together with the locking abutment 45 against the force ofthe spring 48 into the position according to 39. This means that thelocking pin 7 is no longer locked and a passage for the locking pin 7 isenabled or opened. The ejection force storage means 4 can then berelieved of stress and ejects the moveable furniture part 2 in theopening direction OR into an open position OS whereby the locking pin 7passes into the position shown in FIG. 40.

1. A drive device for a moveable furniture part comprising an ejectionelement, an ejection force storage means and a locking device for theejection element, wherein the locking device has a locking pin which isacted upon by the ejection force storage means and which is lockable ina locking position in a latching region of a guide path, wherein theguide path is of a cardioid-shaped configuration and the cardioid-shapedguide path has a stressing portion in which the locking pin is moveableupon stressing of the ejection force storage means and a latchingengagement movement region of the locking pin before the lockingposition in the latching region is reached, wherein the locking pinwhich is acted upon by the stressed ejection force storage means ismoveable braked and/or damped in the latching engagement movement regionand can be placed braked and/or damped into the latching region.
 2. Adrive device as set forth in claim 1, wherein the latching region isspaced in the opening direction of the moveable furniture part from atransitional region which is between the stressing portion and thelatching engagement movement region, preferably by between 0.2 mm and 3mm.
 3. A drive device as set forth in claim 2, wherein the locking pincan be preferably completely uncoupled from a movement of the moveablefurniture part as from attainment of the transitional region so that thelocking pin is moveable into the latching region along the latchingengagement movement region by the ejection force storage means.
 4. Adrive device as set forth in claim 1, wherein there is provided adamping device which is operative between the ejection force storagemeans and the locking pin and which damps the kinetic energy transmittedfrom the ejection force storage means into the locking pin before thelocking position is reached.
 5. A drive device as set forth in claim 4,wherein the kinetic energy acting on the locking pin is reduced by thedamping device only in the latching engagement movement region of thelocking pin.
 6. A drive device as set forth in claim 4, wherein thedamping device is in the form of a travel transmission mechanism.
 7. Adrive device as set forth in claim 6, wherein the locking pin can beplaced in the latching region in cam-controlled relationship by thetravel transmission mechanism.
 8. A drive device as set forth in claim7, wherein the travel transmission mechanism has a control cam by whichthe kinetic energy acting from the ejection force storage means on thelocking pin is preferably steadily increased along the latchingengagement movement region in dependence on the control cam.
 9. A drivedevice as set forth in claim 4, wherein the damping device has amoveable damping element, preferably a rotational damper.
 10. A drivedevice as set forth in claim 9, wherein the damping element includes agear which is mounted in damped rotary relationship, wherein at leastone tooth of the gear can be contacted by the locking pin in thelatching engagement movement region and is moveable in dampedrelationship in the direction of the latching region.
 11. A drive deviceas set forth in claim 1, by a base plate and a slider forming theejection element, wherein the slider is moveable relative to the baseplate and is lockable to the base plate by way of the locking device.12. A drive device as set forth in claim 11, wherein the ejection forcestorage means which is preferably in the form of a tension spring isfixed on the one hand to the base plate and on the other hand to theslider.
 13. A drive device as set forth in claim 11, wherein the lockingpin is mounted rotatably to the slider by way of a locking lever andengages into the guide path in the base plate.
 14. A drive device as setforth in claim 1, wherein the ejection force storage means can be loadedby opening and/or closing the moveable furniture part.
 15. An article offurniture comprising a furniture carcass, a furniture part moveablerelative to the furniture carcass and a drive device as set forth inclaim 1 for the moveable furniture part.
 16. An article of furniture asset forth in claim 15, wherein the base plate of the drive device isarranged on the moveable article of furniture and an entrainment portionwhich can be brought into engagement with the ejection element isarranged on the furniture carcass.